This invention relates generally to air-to-ground radar systems and more particularly to apparatus for on-the-ground testing of such radar systems.
A fundamental ingredient of air-to-ground pulse doppler radar is the relative motion of the radar with respect to the ground. During ground testing of such radar systems there is no motion of the radar system relative to the ground. Therefore, it is rather difficult to generate test signals that have realistic amplitude and doppler histories. The ability to test pulse doppler air-to-ground modes during on-the-ground testing is somewhat restricted because of the difficulty in generating realistic test signals.
A common method of ground testing consists of using a test target generator that can generate only a single range cell of radar return. This method tests only a small part of the radar mode operation. It does not test automatic receiver gain setting algorithms or range-cell to range-cell dynamic range requirements. Furthermore, it does not display amplitude presentation or range/doppler cell registration with multiple targets.
Thus it appears to be desirable to have a means for generating test signals which have realistic amplitude and doppler histories in order to adequately ground test coherent air-to-ground radar systems.